The present invention relates to a universal device for external securement, adapted to protect the projecting end of the surgical pins currently used in general traumatology, in particular in the reduction of osseus fractures of the hand and foot.
The pins now used in traumatology of the hand, have incremental diameters from 0.7 to 2 mm. There exists for the protection of the projecting portion of these pins, an external spherical device pierced diametrically, adapted to receive pins of similar diameters. This device is also provided with a tapping disposed in the equatorial plane, in which a headless screw under the action of a screwdriver applies a point pressure on the pin inserted in the device, such that the protective device is immobilized in rotation and in translation on the pin, preventing it from migrating into the wound. There has been proposed by EP 0 527 204, a spherical universal protective device, provided with a bore for a pin, and a locking screw disposed in a hole which opens into said bore in which is disclosed an insert in the form of a resiliently deformable crescent, which under the locking force of said screw, locks the pin by circumconvolution of the two edges of the insert.
There is thus obtained a protection device which simply matches all of the diameters of the pins with the help of a single bore. The production of such a device is costly, its assembly complex and its use with a pin of a diameter of 2 mm can drive the insert out of the bore diametrically.
So as to overcome these drawbacks, the present invention has for its object to provide a new universal device for the protection of surgical pins, simple in structure and easy to use.
To this end, the invention has for its object an external universal device for the protection of the emergent portion of a surgical pin of any diameter used, of the type comprising a protection element provided with an axial cylindrical through bore in which is disposed a resiliently deformable insert adapted to receive the projecting end of the pin, as well as a locking pin disposed in a tapped hole which opens into said bore, characterized in that the resiliently deformable insert is cylindrical, of a shape and dimension adapted to that of the axial cylindrical bore, which has a distal abutment, the insert, under the influence of the pressure of the screw, deforming and trapping the pin disposed in said insert to prevent any risk of becoming buried.
According to a first embodiment, the axial cylindrical bore is partially tapped and the resiliently deformable insert has a complementary screw thread on its external surface so as to be able to be screwed into said bore. Thus, preferably, the insert is designed according to the dimensions permitting it to be screwed into the axial bore of the protective element.
According to a second embodiment, the resiliently deformable insert is disposed and cemented into the axial cylindrical bore.
According to a third embodiment, the resiliently deformable insert is set in the axial cylindrical bore.
The universal protective device according to the invention, thus permits precise adaptation to all diameters of pin currently used in the reduction of osseus fractures of the hand or foot with a single axial bore, without risk that the insert will be ejected from the bore by use of a pin of a large diameter such as 2 mm.
The resilient property of the insert permits it to deform during screwing of the screw to trap the pin, then to recover its initial shape during unlocking of the screw, which has the effect of freeing the pin.
Such a device according to the invention, can be adapted to surgical pins whose diameter is comprised between 0.7 and 2 mm. However, a device quite identical but designed according to suitable dimensional sizes, can be adapted to pin diameters from 2 to 6 mm and so on.
The universal protective device comprises a protection element which can be of spherical shape, but which could also have a cubic, cylindrical, parallelepipedal, oblong, pyramidal shape or even any other suitable shape.